Revolver feeder for cellulosic materials

ABSTRACT

A revolver feeder for treatment of cellulose containing material comprising a rotor having a plurality of spaces for the material extending axially through the rotor and adapted in different positions of the rotor to be brought into communication with openings formed in, respectively, a feed end plate and a discharge end plate so as during rotation of the rotor to be fed with material and subsequently with treating fluid under high pressure to be dis- charged upon further rotation of the rotor, said end plates being inter- connected by draw bars equally spaced about the circumference of said end plates outside said rotor. Unbalanced pressure forces acting on the end plates due to pressure variations in the spaces of the rotor are equalized by traction force producing devices disposed individually for all or those draw bars positioned adjacent the areas exposed to high outwardly directed pressure forces from said spaces so as to balance the pressure forces and maintain a substantially uniform bearing play between the end plates and the ends of the rotor along the circumference of the rotor. Preferably, each individual traction force producing device contains an automatically operative pressure control device causing production of a traction force counterbalancing an outwardly directed increased pressure from the adjacent space of the rotor. In order to establish a predetermined bearing play or a floating contact, removable bearing discs or sealing discs are interposed between the opposing faces of the rotor and the end plates.

Sept 1l, 1973 R. B. REINHALL 3,758,319

REVOLVER FEEDER FOR CELLULOSIC MATERIALS Fiied Feb. s, 1971 4 Shun-shut 1l ROLP BERTIL REINIIALL,

Inventor ERIC Y; WUNSON, Attorney Sept. 1l, 1973 R. B. REINHALI. 3,758,379

REVOLVER FEEDER FOR CELLULOSIC MATERIALS Filed Feb. 5. 1971 4 shuts-Shelf. 2

ROLF BERTIL REINHALL,

Inventor ERIC Y. MUNSON, Attorney Sept. 1l, 1973 R. B. REINHALL 3,758,379

REVOLVER FEEDER FCR CELLULOSIC MATERIALS 4 Shoots-'Sheet 5 Filed Feb. 3. 1971 Sept. ll, 1973 R. B. REINHALL 3,758,379

REVOLVER FEEDER FCR CELLULOSIC MATERIALS Filed Feb. s, 1971 4 Smets-sheet' 4 Y ROLF BERTIL REINHALL,

Inventor EQTC Y. .'\'1UNSON,AttOrneY United States Patent O 3,758,379 REVOLVER FEEDER FOR CELLULOSIC MATERIALS Rolf Bertil Renhall, Killingevagen 16, Lidingo, Sweden Filed Feb. 3, 1971, Ser. No. 112,326 Claims priority, application Sweden, Feb. 12, 1970, 3,307/70 Int. Cl. D21c 7/06 U.S. Cl. 162-246 3 Claims ABSTRACT OF THE DISCLOSURE A revolver feeder for treatment of cellulose containing material comprising a rotor having a plurality of spaces for the material extending axially through the rotor and adapted in different positions of the rotor to be brought into communication with openings formed in, respectively, a feed end plate and a discharge end plate so as during rotation of the rotor to be fed with material and subsequently with treating Huid under high pressure to be discharged upon further rotation of the rotor, said end plates being interconnected by draw bars equally spaced about the circumference of said end plates outside said rotor. Unbalanced pressure forces acting on the end plates due to pressure variations in the spaces of the rotor are equalized by traction force producing devices disposed individually for all or those draw bars positioned adjacent the areas exposed to high outwardly directed pressure forces from said spaces so as to balance the pressure forces and maintain a substantially uniform bearing play between the end plates and the ends of the rotor along the circumference of the rotor. Preferably, each individual traction force producing device contains an automatically operative pressure control device for causing production of a traction force counterbalancing an outwardly directed increased pressure from the adjacent space of the rotor. In order to establish a predetermined bearing play or a oating contact, removable bearing discs or sealing discs are interposed between the opposing faces of the rotor and the end plates.

BACKGROUND OF THE INVENTION The invention relates to a revolver feeder valve for treatment of cellulose containing material, such as wood chips or the like, at a plurality of stations, and comprising a rotor with a plurality of pockets for the material extending axially through the rotor from end to end and disposed around the centre of the rotor, a feed end plate tightly connected to one end of the rotor and formed with feed openings for feeding material to at least one rotor pocket in a rst position of the rotor feeding into said rotor pocket treating fluid under pressure in at leat one second position, and with a discharge end plate tightly connected to the other end of the rotor and formed with one or more openings for discharge of treating fluid in a third position of rotation of the rotor, the feed end plate and the discharge end plate being interconnected by means of draw bars disposed circumferentially about the end plates and outside of the rotor.

One of the most serious problems with revolver feeder valves of this type are caused by the unbalanced pressure forces acting on the end plates. Thus, that pocket into which the chips are fed is normally under insignificant pressure whereas another pocket into which liquor or steam is supplied, is subjected to high pressure thereby creating la tendency in the end plates to be forced away from the end faces of the rotor at the last mentioned pocket. These unbalancing or unbilasing forces cause rapid and irregular wear of the opposing surfaces of the end plates and the rotor which in turn causes leakage between ICC the lvarious spaces and necessitates regrinding of the sealing surfaces OBJECTS OF THE INVENTION The main object of the invention is to provide a revolver feeder valve in which the unbalancing or biasing forces are compensated wholly or at least substantially so that an essentially constant and uniform wear of the sealing surfaces is obtained.

THE DRAWINGS Further objects and advantages of the invention will become apparent from the following description considered in connection with the accompanying drawings, which form part of this specification and of which:

FIG. l shows an axial section through the revolver feeder, FIG. 2 shows a section through the tightening disc of the feed end plate along the line II-II of FIG. l, FIG. 3 shows a section through the rotor along the line III-III of FIG. l, FIG. 4 shows a section through the sealing disc of the discharge end plate along the line IV-IV of FIG. l, FIG. 5 shows a section through the discharge end plate along the line V-V of FIG. l and FIG. 6 illustrates schematically an automatically operative pressure control device.

DETAILED DESCRIPTION Referring now to the dawings, the revolver feeder illustrated therein has a rotor 1, which has a plurality of sockets 11 extending axially from end to end and by way of example may have the cross-sectional configuration which is shown in FIG. 3. The rotor 1 is driven stepwise by means of a driving device shown in simplified manner in FIG. 3 and comprising a driving ring 25 surrounding the rotor 1 with a driving pawl 26 which cooperates with recesses Y27 in the surface of the rotor located inside the ring 25. The driving ring 25 is rotated alternatively in a forward and backward direction by a cylinder 28 controlled in a conventional manner and having a piston rod 29 which is pivotably attached to an ear 30 on the driving ring. In FIG. 3, the piston rod 29 is shown in its end position of advancing feed and the position of the ear 30 at the end of a return stroke is indicated by dashed lines.

Bearing against the upper plane end of the rotor 1 is a feed end plate 2 with an upper sealing disc 9 which cooperates with a wearing disc 10. The wearing disc 10 is clamped in a bearing bushing 31 inthe central hole of the rotor 1, and mounted in the bushing is a shaft 32 which is non-rotatably connected with both the feed end plate 2 and a discharge end plate 3. The sealing disc 9 is replaceably connected to the end plate 2, by way of example, by means of pins not shown. Lubricant is supplied to the bearing surfaces of the bushing 31 through a nipple 33 and a lubricating channel 34 formed in the shaft 32.

Opposing the lower plane end of the rotor 1 is the discharge end plate 3, to which a sealing disc 14 is secured detachably and non-rotatably, against which disc a wearing disc 13 bears in a sealing manner, which wearing disc is fixed relatively to the rotor 1 and rigidly secured therein by way of example by means of pins (not shown) so that it can be replaced when necessary. The two end plates 2 and 3 have flanges numbered, respectively, 35 and 36 which project for some distance downwards along the outer surface of the cylindrical rotor 1. Formed in each ange is an annular groove 37 and 38, respectively, with an outlet numbered, respectively, 39 and 40, through which liquid leaking out past the sealing surface between associated sealing and wearing discs can escape.

The feed end plate 2 is provided with a feed duct 6 for supplying chips to the pockets 11 through the openings 7 and 8 (FIG. 2) in the end plate 2. In the embodiment shown, there are two tubular ducts for supplying impregnating liquid under pressure through the openings 1S and 16 in the feed end plate into the aligned rotor pockets or channels 11, and ducts for introducing a fluid medium such as steam or liquor through the end plate openings 17 and 18 (FIG. 2) for the purpose of evacuating the aligned rotor pockets or channels. The tubular conduit 19 for the end plate opening 17 is shown in FIG. 1.

The discharge end plate 3 has an outlet tube 21, which connects with a perforate screen 20 in the lower sealing disc 14 through the openings 12 (FIG. 5) and installed together therewith in the discharge end plate. When feeding chips through the conduit 6 and the openings 7 and 8 and the aligned openings in the discs 9 and 10 into the two pockets 11 aligned therewith, air and steam escape through the outlet tube 21. In addition, there is a discharge tube 42, which cooperates with the openings 22 in the lower sealing disc 14 and corresponding openings 43 in the discharge end plate 3. When for example, liquor is supplied to the tubular conduit 19, the treated chips are forced out through the tube 42. For discharge of liquid eventually remaining in the spaces there is provided in the lower sealing disc an opening 44 which cooperates with an outlet opening (not shown) in the discharge end plate 3.

The Various openings in end plates, wearing discs and sealing discs are located in the manner shown in the FIGS. 2, 4 and 5. The openings in the wearing discs are aligned with the openings of the various pockets 11. The openings 8 and 7 thus are located over the openings 20. The openings 15 and 16 have no corresponding openings in the lower sealing disc 14 and the pockets 11 when aligned with the last-mentioned openings are thus closed at the bottom. The openings 17 and 18 are located over the openings 22 and thus chips can be forced out through the tube 42, and the opening 44 which only serves to permit escape of remaining liquid and therefore has no corresponding opening in the feed end plate.

'Ihe end plates 2 and 3 are pressed against the end surfaces of the rotor by the intermediate discs 9 and 10 by means of draw bars 4, one of which is shown in FIG. 1. The draw bars are evenly spaced around the circumferences of the end plates and outside of the rotor. The lower threaded end of the draw bar 4 is clamped in the flange 36 of the discharge end plate 3 by means of nuts 5. The draw bar 4 passes freely through a bore in the flange 35 of the feed end plate 2, and the upper end of the bar is provided with a servomotor comprising a piston 4S in a cylinder 46. The lower extension of cylinder 46 rests on the ange 35 and is preferably rigidly secured thereto. In the shown embodiment, the piston 45 is provided with a guide sleeve 47 which is screwed onA the draw bar 4. The position of the piston on the draw bar is determined by means of a locking nut 48 which is screwed on the draw bar and-bears against the guide sleeve 47 which passes through the upper wall of the cylinder 46 in sealed relationship. Pressure uid chambers 49 and 50, respectively, are formed on opposite sides of the piston 45. The pressure fluid chamber 50 communicates through a pipe 51 with a pressure controlling device 52 and the pressure iluid chamber 49 communicates through a pipe 53 with said device 52.

The pressure controlling device 52 is shown in a highly simplified manner in FIG. 6 together with the piston 4S, the draw bar 4 and the end plates 2, 3. Various detailed realizations of the device 52 are shown and described in the U.S. patent specification No. 2,971,704. The device 52 includes a valve body 54 with a piston which is displaceable within a bore in the valve body. The piston has two piston portions 55 and 56 and a narrower central portion 57. This central portion has a length slightly expeeding the distance between two radially extending recesses S8 and 59 of the bore which latter is sealed against the outside by an end cover 60 and a packing adjacent the piston portion S5. Opening into the adjacent radially extending recess 59 is a conduit 53, 70 from the chamber 49 whereas the conduit 51 from the chamber 50 opens halfways between the last-mentioned recess and the recess 58. Into this recess 58 opens a conduit 71 which communicates with an oil pan or sump 72 from which oil or other pressure fluid under desired pressure is forced by a continuously working pump 74 driven by an electric motor 73 through a conduit 75 into the conduit 70 and the recess 59 and through the conduit S3 into the chamber 49. is an adjustable valve in an overflow conduit 96 extending from the pressure conduit '94 to the sump 72. A bracket 97 rigidly secured to the feed end plate 2 is through a stiff bar 98 iixed onto the valve body 54 and a bracket 99 rigidly secured to the discharge end plate 3 is through a stiff bar 100 attached to the piston 55, 56, 57.

OPERATION OF THE PRESSURE CONTROLLING DEVICE The operation of the pressure controlling device 52 is according to the following. When a high pressure prevails in any of the pockets 11 of the rotor 1 compared with the other pockets 11, the end plates 2, 3 are subjected to an unbalanced pressure which tends to move and bias the end plates from the ends of the rotor 1 Within that zone which is adjacent the pockets 11 which are subjected to high pressure. This results in the valve body 54 for the draw bar or bars 4 located next to the high pressure area being drawn upwards in FIG. 6, whereas the bar 100 Will draw the piston in the valve body 54 downwards. The piston portion 56 will thereby be caused to move downwards relatively to the valve body S4 and thereby shut off the recess 58 and therewith cut of also the return conduit 71 to the sump 72. At the opposite side the recess 59 is gradually exposed. This causes the pressure oil fed by the pump 74 to be conveyed through the conduit 94, 70 and the recess 59 past the central portion 57 of the piston into the conduit 51 and into the chamber 58 under substantially unchanged pressure. As the surface area of the piston 45 facing the chamber 50 is larger than the surface area facing the chamber 49, an excess force is produced in the chamber 50 which displaces the piston 45 in upward direction in the FIGS. 1 and 6 and thereby those portions of the end plates 2 and 3 which tend to be urged away from the end faces of the rotor are forced with great energy against said end faces so that a reliable sealing effect between the end plates and the rotor is always maintained. Thus a predetermined sealing pay is maintained.

It will be clear from the foregoing description, that in the event the end plates should become displaced or biased at some portion of their circumference, so that the play is decreased below a predetermined minimum, the piston 57 will rise until the chamber 59 becomes closed, at which point, pressure fluid will flow only into the chamber 49. This will cause the end plates to move away from the rotor until normal play is restored by the normal operation of the revolver valve. Thus, the one draw bar may be effective to move the end plates in a direction towards the rotor, while another draw bar tends to move the plates in a direction away from the rotor.

By equipping each draw bar 4 or at least those draw bars which are located within zones of the end plates which are exposed to great pressure forces from the pockets 11, with a pressure controlling device 52 it is ensured that the end plates 2, 3 always seal against the ends of the rotor and bear against said ends under constant or at least substantially constant pressure along the whole contact surface whereby irregular Wear of the contact surfaces and deleterious leakage between the pockets 11 is avoided. By providing, according to the invention, replaceable wearing discs and sealing discs the inevitable wear between the sealing surfaces rotating relatively to one another can be compensated for without requiring refinishing work on the end plates and the ends of the rotor.

The shown pressure control device 52 can to advantage be replaced by eg. pneumatic feelers of the type in which nozzles direct an air jet against a reference surface on one end plate or on both end plates and in which the relative displacement of the end plates in axial direction of the rotor causes changes in pressure of the compressed air which is utilized for control of an electric, hydraulic or pneumatic servomotor which increases or reduces the tractive forces in the draw bars in consideration in response to said changes in pressure. In this way axial ldisplacements between the end plates of the order of magnitude of some few microns can be equalized.

Since the novel device eliminates the danger of inclination of the end plates relative to the axis of the rotor, a substantially higher contact pressure between the sealing surfaces can be maintained than has been possible heretofore. However, in order to avoid these high contact pressures from causing too rapid wear, the said sealing and wearing discs are provided which can be manufactured of more wear-resistant material than the other parts of the revolver feeder.

What is claimed is:

1. A revolver feeder for impregnating cellulosic material at a plurality of stations comprising:

(a) a rotor having a plurality of radially spaced openended pockets extending axially from end to end of said rotor;

(b) a feed end plate adjustably bearing against one end of said rotor to seal said end of said pockets;

(c) said feed end plate having feed openings connected to a duct for introducing the material to be treated into said pockets at a rst station of the rotor;

(d) openings connected to a duct for introducing a treating medium under pressure into said pockets at a second station of said rotor;

(e) a discharge end plate adjustably bearing against the opposite end of said rotor to seal the other end of said pockets and having an opening for discharging the impregnated material at a third station;

(f) means for moving said rotor to align the openings in said plates with said pockets;

(g) a plurality of adjustable draw bars circumferentially spaced about said plates to interconnect the same and maintain them in bearing engagement with said rotor, and

(h) control means connected to said draw bars for adjusting said draw bars responsive to different pressures in said pockets effective to move said plates to maintain a predetermined circumferentially balanced bearing play between said rotor and said plates.

2. A revolver feeder according to claim 1 in which said control means comprise a pressure controlling device for sensing the axial displacement of the plates relative to the rotor and effective to actuate a servo motor connected to said draw bars.

3. A revolver feeder according to claim 1 in which said plates are provided with sealing discs bearing against bearing discs carried by the rotor.

References Cited UNITED STATES PATENTS 3,215,591 11/1965 Schnyder 162-246 2,971,704 2/ 1961 Johansson 241-37 3,224,606 12/ 1965 Schnyder 162-246 X S. LEON BASHORE, Primary Examiner A. DANDREA, JR., Assistant Examiner U.S. Cl. X.R. 162-52; 251-175 

